Tri-Town Water Resources

Student Authors: B. Bennett, J. Gallaher, and J. Nitzschke

We would like to thank the Tri-Town Conservation Commissions and Dr. Amy Villamagna for giving us the opportunity to enhance our skills as consultants and creating a stepping stone for future collaborations with Plymouth State University.

Students in the Environmental Science and Policy program at Plymouth State University developed this Story Map website in Spring 2024 to comprehensively review risks to the water resources of the Tri-Town Valley of Easton, Franconia, and Sugar Hill.

The intent of this website is to provide Tri-Town residents with information on the impact of their daily activities on water resources. The Tri-Town Valley is a headwaters watershed, meaning that all the water we have originates within this watershed. The tabs above outline both how the watershed functions and specific threats facing the quality of the water in the watershed. As people gain knowledge about the hydrology of the Tri-Town Valley, they can better understand how to protect water resources (quality and availability) and its surrounding environment. Watershed management involves monitoring, public participation, planning, and restoration. Community education and engagement in watershed management plays a crucial role in informing local decision making as well as in preserving and protecting our shared water resources.

A watershed is an area of land that drains or "sheds" water into a specific waterbody. On its way, the water travels across farm fields, forestland, parking lots, highways, city streets, and backyards. Watersheds can be small, such as those that feed into a local stream, or large, encompassing entire river systems. Watersheds are delineated from the flow of surface water to central basins, making them cross political boundaries frequently; all of the watersheds in the Tri-Town cross at least one town boundary. Water in the Tri-Town area drains towards either the Ammonoosuc River, or the Pemigewasset River, and eventually the Connecticut River, where it ultimately enters the sea.

A variety of waterways and wetlands exist in the Tri-Town area, most in the form of streams, rivers, and brooks. Many of the waterways flow into Echo Lake and Coffin Pond. Franconia contains many small streams which are the headwaters to larger rivers including the Gale River, Upper Pemigewasset River, the East Branch Pemigewasset River and the Ammonoosuc River. The Gale River is the largest river in Franconia and is also a public drinking water supply for the towns of Littleton and Bethlehem. The riparian flood plains of these waterways serve as wetland resources for biodiverse species, including migratory birds, local amphibians, and the range of insects and animals that populate the area.  These wetlands also serve to maintain the level of the ground water below the surface. The surface waters of the Tri-Town area promote a variety of recreation like fishing, boating, swimming, and scenic hiking, improving quality of life for all residents.

The headwater of a river or stream is the farthest point on each of its tributaries upstream from its mouth or estuary into a lake or sea, or its confluence with another river.

Headwaters have strong influence on downstream systems. Headwater streams account for approximately 53% of total river network length in the United States (Nadeau and Rains, 2007), providing services such as runoff storage, nutrient retention, and regional biodiversity. Headwaters provide refuge from predators, competitors, high flow rates, act as spawning and nursery habitats that species migrate to, they provide rich feeding grounds, and thermal refuges. Their small size makes them especially sensitive to disruption. Pollution of headwaters will contribute to pollution of the ground water below them and to the surface water that carries this pollution down the watershed. For these reasons, special vigilance in headwater communities is a matter of best community practice, essential to protect the surface and ground water from pollution threats. 

The screenshot below is from the NH Department of Environmental Services (NHDES) Surface Water Quality Assessment, which allows viewers to find a specific waterway and view a variety of facts related to flow and pollution.

Every two years, NHDES produces an Integrated Report describing the quality of New Hampshire’s surface waters and an analysis of the extent to which all such waters provide for the protection and propagation of a balanced population of shellfish, fish and wildlife, and allow recreational activities in and on the water. Each Watershed Report Card has three components; A one page card that summarizes the overall use support for Aquatic Life Integrity, Primary Contact (i.e. Swimming), and Secondary Contact (i.e. Boating) Designated Uses on every Assessment Unit ID (AUID) within the HUC12.

From the NHDES Surface Water Quality Assessment Viewer waterbody profiles we decided to focus on three major waterways including Ham Branch, Profile Lake, and Echo Lake. Starting with the Ham Branch this river is listed as “good” conditions for swimming and boating, “likely good” for aquatic wildlife, and listed as “poor” for fish consumption. Profile Lake was listed as “good” for the potential of being a water supply, listed as “poor” for fish consumption, and all other categories had no current data available. Lastly, Echo Lake only had available data for fish consumption and health of aquatic life which were both listed as being “poor” (NHDES, 2022).  

Several agencies, both federal and state, monitor waterways throughout their reaches. Some of the most common include the Environmental Protection Agency (EPA), U.S. Geological Survey (USGS), and New Hampshire Department of Environmental Services (NHDES). Below are visuals of locations of where NHDES monitoring sites are. All of the water monitoring sites that are displayed here are labeled as monitoring sites for rivers/streams and lakes/ponds.

Looking into the metadata of these monitoring sites found in NH OneStop, we found that these monitoring sites look at a variety of things, including both biotic and abiotic. Taking counts on a variety of fish species including Brook Trout, Atlantic salmon, Slimy Sculpin, Longnose Sucker Eastern Blacknose Dace as was done on the Wild Ammonoosuc River in Easton. However, also taking levels of coliform, calcium, alkalinity, apparent color, chloride, dissolved oxygen, pH, organic carbon, etc. were taken as metrics of water quality in many lakes and streams in these three towns and throughout the state.

The EPA designed the tool above to provide the public with information about the condition of their local waters based on state, federal, tribal, and local data. The EPA tool displays water quality information on three scales: community, state, and national. On the community level, one can explore:

• Water quality in your local watershed
• Information on swimming, eating fish and aquatic life
• Restoration and protection efforts
• Permitted discharger information
• Identified Issues (impairments and discharge violations)
• Local drinking water information
• Water monitoring information

The community’s water resources of surface and ground water face many threats. The primary factor that impacts the water quality in rivers and lakes is what drains from the land into the water. Threats relevant to the Tri-Town area include  PFAS  and  mercury  from disturbed mineral and bedrock deposits around  abandoned mines  and  logged areas , historical landfills and current landfills such as Casella landfill in Bethlehem, failing infrastructure in  septic systems  and  stream crossings , and runoff from landscape - all of which are exacerbated by  slope  and can degrade headwater habitats. Soils can do an excellent job of filtering contaminants and bacteria; however, some contaminants such as the PFAS category of chemicals can diffuse with the water. While the waters of the Tri-town Valley are headwaters quality, local concentrations of chemicals and heavy metals have been identified in select locations. The quality of private well water, as well as municipal water supplies, should be periodically assessed.

Some waterways of the Tri-Town area contain high levels of PFAS, Per- and poly-fluoroalkyl substances are a group of human-made chemicals (of which there are thousands). These chemicals were developed in the 1940s to repel water or make a surface slippery. They are used in many industrial applications such as automotive, construction, and electronics industries. PFAS have since been adapted for many consumer products and are now common drinking water contaminants throughout the United States. Over time, PFAS have leaked into the soil and water in the Tri-Town Valley from landfills and older industrial sites. PFAS cause issues with the kidneys, liver, thyroid, and more (National Library of Medicine, 2020).

The Dept. of Environmental Services has compiled data and developed an online mapper to share spatially explicit locations. To operate the map, navigate to the waterway you want and click the dot. It will then pull up the information you seek. Pollution levels can be visually interpreted based on color, with red being high PFAS levels and green being below maximum contamination level (MCL) which is 4 ppt for PFOA and PFOS, two of the classifications looked at most specifically by this NHDES mapper (EPA, 2024).

In the bottom right of this image is the concern area for PFAS and PFOA sampling. Just south of downtown Franconia along the Ham Branch, there are several locations of concern from elevated levels of these chemicals. The exact sources of PFAS in the Tri-Town Valley are not currently known, however, the highest level of PFAS recorded in the area was 1,421.90 ppt (parts per trillion, otherwise referred to as nanograms per liter) in a well in Franconia. The MCL for the two most common forms of PFAS, PFOA and PFOS is set by the EPA at 4 ppt (EPA, 2024). The Ambient Groundwater Quality Standards (AGQS) for PFOA at 38 ppt and PFAS at 70 ppt. The combined PFOA and PFAS standards is 70 ppt (NHDES, 2019). These are the quantities of PFOA and PFAS taken from the groundwater samples at the exact site where you see the purple dots. The purple star below these groundwater samples indicates a site that is above the set standards.

Some waterways of the Tri-Town area contain high levels of mercury. Mercury normally works its way into water from the atmosphere and is a non-point source pollutant. Because of the presence of mercury, one should be careful eating fish from the area. NH DES water quality data explicitly shares fish consumption warnings by waterway in the Tri-Town area. Mercury is known to cause neurological issues (World Health Organization 2017).

For the Tri-Towns, one can see that the EPA tool How's My Waterway marks Fish and Shellfish Consumption Condition as “impaired” in 2022 in the Ham Branch and Gale River waterbodies due to high acidity and mercury levels in fish populations. The cause of these conditions is unknown. 

To prevent pollution in public and private waters, septic systems must be properly designed, installed, operated and maintained. Most septic systems malfunction because of inappropriate design (including being undersized for current use) or poor maintenance. Some soil-based systems (those with a drain field) are installed at sites with inadequate or inappropriate soils, excessive slopes, or high ground water tables. These conditions can cause hydraulic failures and contamination of nearby water sources.

• Inspecting your system every 1 to 3 years
• Pumping the tank every 3 to 5 years or as needed
• Avoiding excess water use (e.g. spreading out laundry use over the week)
• Flushing only human waste and toilet paper down the toilet.

The frequency for pumping the septic tank depends on the tank size, number of people in the household, the water habits and use, if a garbage disposal is used, and the amount of solids accumulated in the tank. A rule of thumb is to pump the tank when the solids are two-thirds of the volume in the tank. Routine maintenance is the responsibility of the home or property owner. If you rent a home, you have responsibility for the proper use and operation of the system (NHDES 2024).

• Water and sewage from toilets, drains, and sinks backing up into the home’s plumbing
• Bathtubs, showers, and sinks draining very slowly
• High levels of nitrates or coliform bacteria in surface waters or drinking water wells

Remember: Whenever the water table is high or your sewage system is threatened by flooding there is a risk that sewage will back up into your home. The only way to prevent this backup is to relieve pressure on the system by using it less.

NH Department of Environmental Services - Subsurface Systems Bureau

For general septic system questions and Reviewer of the Day

Office Phone:  (603) 271-3501 

Active or past mining activities can alter the geochemistry of watersheds. Mines that closed before 1977 are not required by federal law to be remediated, even though those mines, processing facilities, and tailings piles continue to release pollutants. Legacy pollutants from mines abandoned before 1977 may persist within river, steam, and lake sediments. Flooding in areas of disturbance can exacerbate water pollution that's attributed to mining.

The Tri-Town area was a large iron mining location, which led to its rapid development. There were two separate iron works in Franconia during the 19th century. Copper deposits riddled the landscape which were mined continuously for over 80 years.  

When conducting residential projects in NH, having somebody conduct an assessment on the geology during design and construction is not common, which puts the responsibility on the contractor for identifying problems and requesting engineering expertise when needed.  State and local construction codes require geotechnical explorations prior to construction of commercial projects so as not to disturb glacial till that may contain hazardous materials leftover from mining activities. 

Logging can significantly impact sediment levels in local water resources through several mechanisms: 

Soil Erosion: When trees are logged, the protective canopy and root systems that help hold soil in place are removed. This makes soil more vulnerable to erosion by rain and wind, leading to increased sediment runoff into nearby waterways. 

Stream Bank Stability: Removing trees from riparian zones (areas adjacent to water bodies) can destabilize stream banks. Without the root systems to anchor soil, banks can erode more easily, contributing sediment to the water. 

Private, conserved in orange, municipal in pink, mostly private, non-conserved in yellow. 

Forestry best management practices (BMPs) are used to protect water quality during timber harvests and other forest management activities. BMPs ensure that the equipment used in timber harvests and silvicultural activities like forest thinnings don’t inadvertently push sediment or brush into nearby waterways or promote erosion of stream banks. There is no federal law that requires forestry BMPs; in fact, the Clean Water Act exempts normal silvicultural activities from National Pollutant Discharge Elimination System (NPDES) permitting requirements. 

Click here to view New Hampshire Best Management Practices for Erosion Control on Timber Harvesting Operations: 

Erosion of Sloped Terrains: The Tri-Towns are in a hilly and mountainous region. Steep slopes are more susceptible to erosion, especially during heavy rainfall or snowmelt events. Sediment from eroded slopes can be transported into water bodies, negatively impacting water quality. The more that soil erosion is present, the less vegetation can grow on that land.

Maintain a buffer. If your property borders a body of water, use native plants to create a buffer along the waterway that can remain undisturbed. This area supports filtration and lowers the concentration of pollutants and other harmful substances entering the waterway.

Create a rain-friendly yard. A rain garden is an easy and attractive way to capture runoff, especially when paired with gutters and downspouts. These shallow areas can be planted with herbaceous and woody vegetation that helps infiltrate and filter water into the ground. This helps to replenish the groundwater that feeds wells and waterways, and slow the flow to local waterways.

Choose native plants. Adapted to the local climate, native plants are more drought- and flood-tolerant than their non-native counterparts and often require less fertilizer and pest control. Many native plants have deeper and more efficient root systems that can better absorb rainwater and control erosion. 

Water flowing over yards, driveways, and streets during storms carries everything it comes in contact with – eroded soil, pesticides, fertilizers, oil and grease, leaves, and litter – into storm drains and streams. Even small rainstorms can wash pollutants into waterways. Small changes in yards across town add up to a big impact on both the quantity and quality of our storm water runoff.

Threats to water availability include proximity to aquifers, occurrence of  flooding  and  droughts,  and  slope and aspect  of topography, all of which affect infrastructure including private and municipal wells and  stream crossings . Due to changing climate, the frequency of these weather events is increasing.

An aquifer is a body of rock and/or sediment that holds groundwater. Groundwater is the word used to describe precipitation that has infiltrated the soil beyond the surface and collected in empty spaces underground (National Geographic 2024). Aquifers ensure the water supply of many in the Tri-Town Valley and are essential to the continuation of the towns. When we have a rainy spring or summer, people often assume that the aquifers can recharge themselves. New Hampshire’s aquifers are dependent on the slow, steady spring melt of snowpack. Recent years of relatively little snowpack combined with unseasonably hot weather and heavy rain events have led to flooding rather than a recharge of our aquifers. The map below shows the aquifer flow capacity (recharge) areas of the Tri-Town region. These areas are where water flows down into the aquifer from the ground surface. It is important to protect aquifer recharge areas by preventing pollution from reaching them and allowing these areas to recharge to their maximum extent. 

Lower water levels in our aquifers affect the quality of our drinking water. Shallow wells begin to dry up and people must dig deeper to find water. Lower water levels can result in muddy tasting water, more microorganisms, and bacteria in our drinking water causing fevers, diarrhea, nausea, and other illnesses (EPA 2024). Just as humans do, our ecosystem needs water to survive. When water levels get too low, wildlife and vegetation must compete for water.

South-facing Slopes: will have less water to work with throughout most of the year, with the exception of heavy snowfall which they are equal at that time. This is because the south absorbs the most sunlight since it is the direction closest to the equator. North-facing slopes have consistent water year-round and are more resistant to drying effects of regional drought. Individuals should familiarize themselves with which way their land faces and try to dig their well where it will contain the most water.  

Flooding has the potential to exacerbate the effects of all of the forms of pollution listed in this website. Floodwaters carry the contaminants present in soils, waste sites, mines, septic systems and more into water resources, increasing water pollution levels. Flooding can also damage infrastructure such as roads, stream crossings, and can overwhelm sewage treatment systems, leading to sewage overflow. In the state of New Hampshire, climate is changing. Temperatures have risen more than 3°F since 1900, total annual precipitation has been above average from 2005-2020, and the frequency of extreme weather events, specifically flooding, has increased (NH Dept. of Health and Human Services 2024).

The National Flood Hazard Layer (NFHL) shown below is an interactive map that spatially visualizes flood zones and differentiates between 1% and 0.2% annual chances of flood hazards, as well as regulatory, special, and undetermined flood zones. Sections of each of the Tri-Towns are in the flood zones. The large section of flood zone area south of Franconia is along the Ham Branch and includes the section that was mentioned in the areas of concern for PFAS and PFOA levels that were above standard.

Additionally, a large percentage of this flood area is in heavily clustered residential and commercial areas of Franconia. Looking at land use maps the area just above the large flood zone area along the Ham Branch has the highest intensity of development in the Tri-Town. Other than this developed area though, the rest of the significant flood area along the Ham Branch is either a wetland or used for growing hay or as pasture land.

Wetlands can help out the situation of sediment erosion into waterways by acting as catching reservoirs of polluted runoff. Whether it is sediment or chemical pollution wetlands can be great natural filters before runoff enters larger bodies of water.

One of the most important functions of wetlands is their capacity to control flooding, thereby protecting people and property. Wetlands help control floodwaters by storing excess water during heavy periods of rain and snowmelt. During storm events and spring thaws, vegetated wetlands receive runoff from upland areas and water that overflows from rivers and streams, and lakes and ponds.

Wetlands are integral parts of dealing with pollution in the environment. Filling in wetlands makes it extremely challenging to bring back the crucial functionality that they serve. Man-made wetlands also exist, but their functionality is considerably less inferior to that of a natural, unaltered wetland. Beneficially economically to society research shows that wetlands can be attributed to saving towns and municipalities large amounts of money if left conserved and largely unaltered. With much of the area in the Tri-Town being conserved by White Mountain National Forest, the wetlands in this area are a lot better off than many other places that are more prone to urbanization.

Droughts happen when an area receives below average rainfall for an extended period of time, which results in lower water levels across the whole area. People often see New Hampshire as a water rich region of the country; however, moderate to severe droughts have occurred in New Hampshire in 11 out of the last 20 years. Droughts directly affect the amount of water available in our aquifers. During recent droughts, wildlife started coming into human inhabited spaces in search for food and water.

• Avoid non-essential uses such as: watering your lawn, car washing
• Reduce length of showers
• Fix leaks across your house: toilet leaks, faucet leaks, and shower leakage
• Update water appliances to increase water efficiency where possible. If using an older washer, reduce water consumption by consolidating laundry into a full load
• If your well dries up or begins to become polluted (taste and color) alert your well contractor and you may need to dig deeper

The National Integrated Drought Information System (NIDIS) depicts the location and intensity of drought across the country. The map uses 5 classifications: Abnormally Dry (D0), Moderate Drought (D1), severe drought (D2), extreme drought (D3), and exceptional drought (D4). This map is used by the U.S. Department of Agriculture (USDA) to inform some disaster declarations and loan eligibility. Individual states and water supply planning may use additional information to inform their actions. The site also has maps that show historical and future predictions of precipitation, temperature, stream flow condition and soil moisture conditions in U.S. states. NIDIS & its partners issue regional status updates regarding drought conditions, outlooks/forecasts, and local impacts which can be sent right to your email (sign up list and additional resources can be found at the bottom of the webpage).

A stream crossing is a man-made structure, such as a culvert or bridge, where roads, railroads, or trails cross over streams, rivers, lakes, and wetlands. Currently, there are over 22,000 road-stream crossings in New Hampshire. In the Tri-Town area, 98% of the road-stream crossings are too old, too damaged, or too small to be effective as aquatic wildlife crossings and flood mitigation. When these road stream crossings are too small, they can exacerbate flooding, damage a road’s structural integrity, erode landscapes, and prevent fish and other aquatic wildlife from migrating to spawn.  

Aquatic Organism Passage (AOP) Score reflects various parameters collected in the field:

• Amount of obstructions such as wood, debris, screens that restrict the movement of aquatic organisms
• The amount of natural sediment in the stream crossing
• Water in the crossing that is shallow or accelerated flow

Geomorphic Compatibility (GC) Score evaluates how the stream crossing structure is fitted with the natural form of the stream and how it alters water and sediment transport

• Size of structure compared to width of stream channel
• Evaluates bank stability by observing erosion from high velocity water
• The angle of the stream where it enters the stream crossing structure (sharp angles contribute to bank erosion and sediment deposition)

These charts show the importance of culverts and how many we have that are currently usable and how many are impaired. It is important to note that when one constructs culverts correctly, they do not cause nearly as many problems during floods. With ~20% of crossings being completely Impermeable that can have a large effect on fish populations as well as increase rates of erosion on the surrounding banks. If culverts become clogged at their entrance, it can cause water levels to increase resulting in flooding of neighboring roads and landscapes. Replacing these culverts before they cause large issues would save the towns upwards of millions of dollars in roadwork and culvert replacements as well as residential destruction.

The National Culvert Removal, Replacement, and Restoration Grant Program

• Annual grant program
• Eligible applicants include - Tribes, States, and Local governments
• Projects that include replacing, restoring, or removing culverts that meaningfully restore fish passage

American Rescue Plan Act of 2021 - Culvert Flood Risk Assistance Grant Program

• Grant utilizes American Rescue Plan Act funds
• Eligible applicants include New Hampshire's municipalities and non-governmental organizations
• Grant program awards up to 400,000 dollars for stream crossing that are highly susceptible to flooding

Flood Risk - Stream crossings are a vital part of New Hampshire's transportation network. When a culvert or bridge is undersized, it restricts water and sediment flow. As intense rainstorms become more frequent, inadequate sized culverts are unable to handle high volumes of water. This causes water flow to travel over the surface of the road or wash out the road materials.

Stream Connectivity - Aquatic animals such as the American shad, Northern Redbelly Dace, Brook Trout, amphibians, and invertebrates are crucial pieces to a healthy freshwater ecosystem. Improperly installed or degraded stream crossings act as a barrier for aquatic organisms, which ultimately reduces their ability to breed, nest, and find overwintering sites.

Freshwater fish and macroinvertebrates, from the sub organismal to community level, exhibit excellent response signals to stressors and as bio-indicators of water quality.  If their quality of health is poor, it is reflective of poor water quality. Many of these species are also sight-feeding predators and depend on relatively clear water; therefore, any activities that cause long-term increases in turbidity (e.g., construction projects, forestry practices, livestock grazing) will be deleterious.

Sediment Transport - Streams and rivers help transport essential sediment, nutrients, and organic material downstream and onto floodplains. When a stream crossing is undersized the velocity of water within the culvert increases, causing erosion to banks and stream beds. Properly installed culverts are crucial for water and habitat quality.

Sediment is the loose sand, clay, silt and other soil particles that settle at the bottom of a body of water. Sediment can come from soil erosion or from the decomposition of plants and animals. Wind, water and ice help carry these particles to rivers, lakes and streams. 

Sediment entering stormwater degrades the quality of water for drinking, wildlife and the land surrounding streams in the following ways:  

• Sediment fills up storm drains and catch basins to carry water away from roads and homes, which increases the potential for flooding.  
• Water polluted with sediment becomes cloudy, preventing animals from seeing food.  
• Murky water prevents natural vegetation from growing in water. 
• Sediment in stream beds disrupts the natural food chain by destroying the habitat where the smallest stream organisms live and causing massive declines in fish populations.  
• Sediment increases the cost of treating drinking water and can result in odor and taste problems. 

• Sweep sidewalks and driveways instead of hosing them off. Washing these areas results in sediment and other pollutants running off into streams, rivers and lakes.
• Notify local government officials when you see sediment entering streets or streams near a construction site.
• Avoid mowing within 10 to 25 feet from the edge of a stream or creek. This will create a safe buffer zone that will help minimize erosion and naturally filter stormwater runoff that may contain sediment.
• Either wash your car at a commercial car wash or on a surface that absorbs water, such as grass or gravel.

The NEPAssist tool created by the EPA generates a report on compromised resources. There are various layers that can be turned on and off. The report will provide additional information and follow up links to further research.

Based on the finding of our NRI in regards to the Stream Crossing Initiative, we recommend taking action on submitting applications for the Stream Crossing Initiative program in regards to the stream crossings identified as "no passage" or "reduced passage" to improve the quality, function, and health of aquatic ecosystems. This will help maintain healthy ecosystems and preserve biodiversity. A few ways you can go about this include constructing an overpass or underpass or more realistically promoting caution in these areas. By taking action on even a few of the opportunities identified in this Story Map, you could work together to ensure the long-term sustainability of the Tri-Town area's natural resources.

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